Design and Analysis of SD_DWCA - A Mobility based clustering of Homogeneous MANETs

This paper deals with the design and analysis of the distributed weighted clustering algorithm SD_DWCA proposed for homogeneous mobile ad hoc networks. It is a connectivity, mobility and energy based clustering algorithm which is suitable for scalable ad hoc networks. The algorithm uses a new graph parameter called strong degree defined based on the quality of neighbours of a node. The parameters are so chosen to ensure high connectivity, cluster stability and energy efficient communication among nodes of high dynamic nature. This paper also includes the experimental results of the algorithm implemented using the network simulator NS2. The experimental results show that the algorithm is suitable for high speed networks and generate stable clusters with less maintenance overhead

Full-duplex wireless communications: challenges, solutions and future research directions

The family of conventional half-duplex (HD) wireless systems relied on transmitting and receiving in different time-slots or frequency sub-bands. Hence the wireless research community aspires to conceive full-duplex (FD) operation for supporting concurrent transmission and reception in a single time/frequency channel, which would improve the attainable spectral efficiency by a factor of two. The main challenge encountered in implementing an FD wireless device is the large power difference between the self-interference (SI) imposed by the device’s own transmissions and the signal of interest received from a remote source. In this survey, we present a comprehensive list of the potential FD techniques and highlight their pros and cons. We classify the SI cancellation techniques into three categories, namely passive suppression, analog cancellation and digital cancellation, with the advantages and disadvantages of each technique compared. Specifically, we analyse the main impairments (e.g. phase noise, power amplifier nonlinearity as well as in-phase and quadrature-phase (I/Q) imbalance, etc.) that degrading the SI cancellation. We then discuss the FD based Media Access Control (MAC)-layer protocol design for the sake of addressing some of the critical issues, such as the problem of hidden terminals, the resultant end-to-end delay and the high packet loss ratio (PLR) due to network congestion. After elaborating on a variety of physical/MAC-layer techniques, we discuss potential solutions conceived for meeting the challenges imposed by the aforementioned techniques. Furthermore, we also discuss a range of critical issues related to the implementation, performance enhancement and optimization of FD systems, including important topics such as hybrid FD/HD scheme, optimal relay selection and optimal power allocation, etc. Finally, a variety of new directions and open problems associated with FD technology are pointed out. Our hope is that this treatise will stimulate future research efforts in the emerging field of FD communication

Interference in vehicle-to-vehicle communication networks - analysis, modeling, simulation and assessment

In wireless vehicular communication networks the periodic transmission of status updates by all vehicles represents a basic service primitive, in particular for safety related applications. Due to the limited communication resources the question raises how much data each node may provide such that the quality of service required by applications can still be guaranteed under realistic interference conditions. Local broadcasts capacity is introduced and analyzed to tackle this open question

TRW-MAC: A thermal-aware receiver-driven wake-up radio enabled duty cycle MAC protocol for multi-hop implantable wireless body area networks in Internet of Things

Implantable Wireless Body Area Network (IWBAN), a network of implantable medical sensors, is one of the emerging network paradigms due to the rapid proliferation of wireless technologies and growing demand of sophisticated healthcare. The wireless sensors in IWBAN is capable of communicating with each other through radio frequency (RF) link. However, recurring wireless communication inside the human body induces heat causing severe thermal damage to the human tissue which, if not controlled, may appear as a threat to human life. Moreover, higher propagation loss inside the human body as well as low-power requirement of the sensor nodes necessitate multi-hop communication for IWBAN. A IWBAN also requires meeting certain Quality of Service demands in terms of energy, delay, reliability etc. These pressing concerns engender the design of TRW-MAC: A thermal-aware receiver-driven wake-up radio enabled duty cycle MAC protocol for multi-hop IWBANs in Internet of Things. TRW-MAC introduces a thermal-aware duty cycle adjustment mechanism to reduce temperature inside the body and adopts wake-up radio (WuR) scheme for attaining higher energy efficiency. The protocol devises a wake-up estimation scheme to facilitate staggered wake-up schedule for multi-hop transmission. A superframe structure is introduced that utilizes both contention-based and contention free medium access operations. The performance of TRW-MAC is evaluated through simulations that exhibit its superior performance in attaining lower thermal-rise as well as satisfying other QoS metrics in terms of energy-efficiency, delay and reliability